An EPS (evolved packet system) includes two parts, which are an access network and a core network, and a system architecture in a non-roaming scenario is shown in FIG. 1. A radio access network of the EPS is an evolved universal terrestrial radio access network (E-UTRAN), which is configured to implement all functions related to evolved network radio part. Key logical network elements of the core network include a mobility management entity (MME), a serving gateway (S-GW) and a packet data network gateway (P-GW). The MME mainly completes processing of signaling-plane functions, for example, user authentication and switching, and mobility management and bearer management of an idle-state terminal. The S-GW is a user-plane function entity for completing routing and forwarding of packet data, and is used as a data anchor in a 3GPP system to terminate an interface of the E-TURAN; and is additionally a local mobility management anchor in an E-TURAN handover scenario in a geographic region. The P-GW is a gateway connected to an external data network, and is a user-plane anchor between a 3GPP access network and a non-3GPP access network. User equipment may access external packet data networks (PDN) by connecting to a PDN link created by the P-GW. These PDNs may be the Internet, a virtual private network (VPN), an IP multimedia service (INS) network, or a Wireless Application Protocol (WAP) network that is provided by an operator. In actual network deployment, logical network elements S-GW and P-GW may be separated or may be integrated; and with a few exceptions (for example, roaming), the logical network elements S-GW and P-GW are integrally deployed.
OpenFlow reconstructs conventional physically fixed hardware into a dynamically variable software-defined networking (SDN), implementing separation between a control plane and a forwarding plane. When an SDN architecture is introduced into an SAE network, a control-plane function and a forwarding-plane function that are of a gateway may be separated from each other, and therefore an architecture shown in FIG. 2 can be obtained.
It can be seen from the figure that the control plane and the forwarding plane that are of the gateway have been separated from each other, the control plane of the gateway may decide a data processing rule related to the user equipment (UE), that is, a flow table, and send the flow table to the forwarding plane of the gateway by using an interface (for example, an OpenFlow interface) between the control plane and the forwarding plane; and the forwarding plane of the gateway implements processing of a data packet of the user equipment (UE) according to the rule.
In the SAE network, a gateway includes an SGW and a PGW. Therefore, after control and forwarding are separated, there may be two roles on both the control plane and the forwarding plane. For example, on the control plane, the roles may be an SGW-C and a PGW-C, and in addition, on the forwarding plane, the roles may be an SGW-U and a PGW-U. During deployment in an actual network, separated deployment or integrated deployment may be performed on control planes and forwarding planes as required.
In the prior art, when integrated deployment is performed on forwarding planes, but separated deployment is performed on control planes, that multiple control gateways control a same forwarding gateway is caused, which probably results in a control policy conflict, and affects a normal forwarding function of the gateway.